Renal nerve activity and exaggerated natriuresis in conscious spontaneously hypertensive rats.
Renal nerve activity and exaggerated natriuresis in conscious spontaneously hypertensive rats.
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清醒自发性高血压大鼠的肾神经活动和过度的尿钠排泄。
DOI：
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发表时间：
1981
期刊：
影响因子：
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通讯作者：
P. Thoren
中科院分区：
文献类型：
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作者：
S. Ricksten;T. Yao;G. Di Bona;P. Thoren
在人类和动物高血压中，体积负荷引起的钠尿过度，主要是由于肾小管重吸收受到抑制。为了探讨肾脏交感神经活动的改变是否有助于这种反应，我们将有意识的雄性自发性高血压大鼠（SHR）与正常的雄性Wistar Kyoto大鼠（WKR）相比，暴露于等渗盐水负荷中。观察平均动脉压、心率、肾交感神经活动和尿钠排泄的60分钟对照缺水期后，开始用等渗生理盐水（0.2 ml/min X 100 g b.w.）进行60分钟静脉扩张，随后进行60分钟缺水恢复期。在对照期，SHR的钠排泄量已经显著增加。在容量负荷和随后的恢复期，与WKR相比，SHR出现明显夸张的钠尿。此外，容量负荷降低了所有动物的肾交感神经活动，但在SHR中更明显。此外，容量负荷降低了两组的平均动脉压和心率。提示SHR在容积负荷时肾交感神经活动反射抑制的增强来自于心脏机械感受器，这在一定程度上解释了SHR中尿钠的夸大。这种增强的“体积”反射反应可能是由于SHR中全身静脉顺应性降低，从而增加了中央充盈和心脏受体激活。
Exaggerated natriuresis upon volume loading occurs in both human and animal hypertension and is mainly due to suppressed tubular reabsorption. To explore whether altered renal sympathetic activity contributes to this response, conscious male spontaneously hypertensive rats (SHR) were exposed to isotonic saline loading in comparison with normotensive male Wistar Kyoto rats (WKR). After a 60 min control hydropenic period, during which mean arterial pressure, heart rate, renal sympathetic nerve activity and urinary sodium excretion were followed, a 60 min period of intravenous volume expansion with isotonic saline (0.2 ml/min X 100 g b.w.) was started followed by a 60 min hydropenic recovery period. Already during the control period sodium excretion was significantly higher in SHR. During the volume load and subsequent recovery period a clearly exaggerated natriuresis occurred in SHR compared with WKR. Further, volume loading reduced renal sympathetic nerve activity in all animals, but significantly more in SHR. Moreover, volume loading reduced mean arterial pressure and heart rate in both groups. It is suggested that the accentuated reflex inhibition of renal sympathetic activity in SHR upon volume loading emanates from cardiac mechanoreceptors and partly explains the exaggerated natriuresis in SHR. This augmented "volume' reflex response is probably due to reduced systemic venous compliance in SHR with a consequently increased central filling and cardiac receptor activation.